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From: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
To: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>,
	Matti Vaittinen <mazziesaccount@gmail.com>
Cc: Mark Brown <broonie@kernel.org>,
	Kees Cook <keescook@chromium.org>,
	Andy Shevchenko <andy.shevchenko@gmail.com>,
	Zhang Rui <rui.zhang@intel.com>,
	Guenter Roeck <linux@roeck-us.net>,
	"agross@kernel.org" <agross@kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	linux-power <linux-power@fi.rohmeurope.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-renesas-soc@vger.kernel.org" 
	<linux-renesas-soc@vger.kernel.org>,
	"linux-arm-msm@vger.kernel.org" <linux-arm-msm@vger.kernel.org>,
	"bjorn.andersson@linaro.org" <bjorn.andersson@linaro.org>,
	"lgirdwood@gmail.com" <lgirdwood@gmail.com>,
	"robh+dt@kernel.org" <robh+dt@kernel.org>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Amit Kucheria <amitk@kernel.org>,
	Matteo Croce <mcroce@microsoft.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Petr Mladek <pmladek@suse.com>,
	"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
	Mike Rapoport <rppt@kernel.org>,
	Josef Bacik <josef@toxicpanda.com>,
	Kai-Heng Feng <kai.heng.feng@canonical.com>,
	linux-pm@vger.kernel.org
Subject: [PATCH v9 03/10] thermal: Use generic HW-protection shutdown API
Date: Mon, 10 May 2021 14:29:01 +0300	[thread overview]
Message-ID: <85d0225cd0e287ec9a7b43709400794c5cf470d5.1620645507.git.matti.vaittinen@fi.rohmeurope.com> (raw)
In-Reply-To: <cover.1620645507.git.matti.vaittinen@fi.rohmeurope.com>

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The hardware shutdown function was exported from kernel/reboot for
other subsystems to use. Logic is copied from the thermal_core. The
protection mutex is replaced by an atomic_t to allow calls also from
an IRQ context.

Use the exported API instead of implementing own just for the
thermal_core.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>

---
Changelog:
v9:
 - Update the thermal documentation
v8:
 - new patch (change added in v7, splitted in own patch at v8)

Use the exported API instead
---
 .../driver-api/thermal/sysfs-api.rst          | 24 +++----
 drivers/thermal/thermal_core.c                | 63 ++-----------------
 2 files changed, 13 insertions(+), 74 deletions(-)

diff --git a/Documentation/driver-api/thermal/sysfs-api.rst b/Documentation/driver-api/thermal/sysfs-api.rst
index 4b638c14bc16..c93fa5e961a0 100644
--- a/Documentation/driver-api/thermal/sysfs-api.rst
+++ b/Documentation/driver-api/thermal/sysfs-api.rst
@@ -740,21 +740,15 @@ possible.
 5. thermal_emergency_poweroff
 =============================
 
-On an event of critical trip temperature crossing. Thermal framework
-allows the system to shutdown gracefully by calling orderly_poweroff().
-In the event of a failure of orderly_poweroff() to shut down the system
-we are in danger of keeping the system alive at undesirably high
-temperatures. To mitigate this high risk scenario we program a work
-queue to fire after a pre-determined number of seconds to start
-an emergency shutdown of the device using the kernel_power_off()
-function. In case kernel_power_off() fails then finally
-emergency_restart() is called in the worst case.
+On an event of critical trip temperature crossing the thermal framework
+shuts down the system by calling hw_protection_shutdown(). The
+hw_protection_shutdown() first attempts to perform an orderly shutdown
+but accepts a delay after which it proceeds doing a forced power-off
+or as last resort an emergency_restart.
 
 The delay should be carefully profiled so as to give adequate time for
-orderly_poweroff(). In case of failure of an orderly_poweroff() the
-emergency poweroff kicks in after the delay has elapsed and shuts down
-the system.
+orderly poweroff.
 
-If set to 0 emergency poweroff will not be supported. So a carefully
-profiled non-zero positive value is a must for emergency poweroff to be
-triggered.
+If the delay is set to 0 emergency poweroff will not be supported. So a
+carefully profiled non-zero positive value is a must for emergency
+poweroff to be triggered.
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index d20b25f40d19..10a2d8e1cacf 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -36,10 +36,8 @@ static LIST_HEAD(thermal_governor_list);
 
 static DEFINE_MUTEX(thermal_list_lock);
 static DEFINE_MUTEX(thermal_governor_lock);
-static DEFINE_MUTEX(poweroff_lock);
 
 static atomic_t in_suspend;
-static bool power_off_triggered;
 
 static struct thermal_governor *def_governor;
 
@@ -327,70 +325,18 @@ static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
 		       def_governor->throttle(tz, trip);
 }
 
-/**
- * thermal_emergency_poweroff_func - emergency poweroff work after a known delay
- * @work: work_struct associated with the emergency poweroff function
- *
- * This function is called in very critical situations to force
- * a kernel poweroff after a configurable timeout value.
- */
-static void thermal_emergency_poweroff_func(struct work_struct *work)
-{
-	/*
-	 * We have reached here after the emergency thermal shutdown
-	 * Waiting period has expired. This means orderly_poweroff has
-	 * not been able to shut off the system for some reason.
-	 * Try to shut down the system immediately using kernel_power_off
-	 * if populated
-	 */
-	WARN(1, "Attempting kernel_power_off: Temperature too high\n");
-	kernel_power_off();
-
-	/*
-	 * Worst of the worst case trigger emergency restart
-	 */
-	WARN(1, "Attempting emergency_restart: Temperature too high\n");
-	emergency_restart();
-}
-
-static DECLARE_DELAYED_WORK(thermal_emergency_poweroff_work,
-			    thermal_emergency_poweroff_func);
-
-/**
- * thermal_emergency_poweroff - Trigger an emergency system poweroff
- *
- * This may be called from any critical situation to trigger a system shutdown
- * after a known period of time. By default this is not scheduled.
- */
-static void thermal_emergency_poweroff(void)
+void thermal_zone_device_critical(struct thermal_zone_device *tz)
 {
-	int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
 	/*
 	 * poweroff_delay_ms must be a carefully profiled positive value.
-	 * Its a must for thermal_emergency_poweroff_work to be scheduled
+	 * Its a must for forced_emergency_poweroff_work to be scheduled.
 	 */
-	if (poweroff_delay_ms <= 0)
-		return;
-	schedule_delayed_work(&thermal_emergency_poweroff_work,
-			      msecs_to_jiffies(poweroff_delay_ms));
-}
+	int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
 
-void thermal_zone_device_critical(struct thermal_zone_device *tz)
-{
 	dev_emerg(&tz->device, "%s: critical temperature reached, "
 		  "shutting down\n", tz->type);
 
-	mutex_lock(&poweroff_lock);
-	if (!power_off_triggered) {
-		/*
-		 * Queue a backup emergency shutdown in the event of
-		 * orderly_poweroff failure
-		 */
-		thermal_emergency_poweroff();
-		orderly_poweroff(true);
-		power_off_triggered = true;
-	}
-	mutex_unlock(&poweroff_lock);
+	hw_protection_shutdown("Temperature too high", poweroff_delay_ms);
 }
 EXPORT_SYMBOL(thermal_zone_device_critical);
 
@@ -1538,7 +1484,6 @@ static int __init thermal_init(void)
 	ida_destroy(&thermal_cdev_ida);
 	mutex_destroy(&thermal_list_lock);
 	mutex_destroy(&thermal_governor_lock);
-	mutex_destroy(&poweroff_lock);
 	return result;
 }
 postcore_initcall(thermal_init);
-- 
2.25.4


-- 
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =] 

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  parent reply	other threads:[~2021-05-10 11:47 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-10 11:26 [PATCH v9 00/10] Extend regulator notification support Matti Vaittinen
2021-05-10 11:27 ` [PATCH v9 01/10] dt_bindings: Add protection limit properties Matti Vaittinen
2021-05-10 11:28 ` [PATCH v9 02/10] reboot: Add hardware protection power-off Matti Vaittinen
2021-05-12  8:20   ` Petr Mladek
2021-05-12 12:00     ` Vaittinen, Matti
2021-05-13  8:34       ` Petr Mladek
2021-05-17  4:57         ` Matti Vaittinen
2021-05-10 11:29 ` Matti Vaittinen [this message]
2021-05-10 11:29 ` [PATCH v9 04/10] regulator: add warning flags Matti Vaittinen
2021-05-10 11:29 ` [PATCH v9 05/10] regulator: IRQ based event/error notification helpers Matti Vaittinen
2021-05-11  4:54   ` Matti Vaittinen
2021-05-10 11:30 ` [PATCH v9 06/10] regulator: add property parsing and callbacks to set protection limits Matti Vaittinen
2021-05-10 11:30 ` [PATCH v9 07/10] dt-bindings: regulator: bd9576 add FET ON-resistance for OCW Matti Vaittinen
2021-05-10 11:30 ` [PATCH v9 08/10] regulator: bd9576: Support error reporting Matti Vaittinen
2021-05-10 11:31 ` [PATCH v9 09/10] regulator: bd9576: Fix the driver name in id table Matti Vaittinen
2021-05-10 11:31 ` [PATCH v9 10/10] MAINTAINERS: Add reviewer for regulator irq_helpers Matti Vaittinen

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